1. Field of the Invention
The present invention relates to an image forming apparatus of an ink jet system, which ejects an ink liquid from an ink head to form an image on an image forming medium, and a method of managing the apparatus at the time of interruption of power supply.
2. Description of the Background Art
A method of managing an image forming apparatus of an ink jet system at the time of interruption of power supply has been described, for example, in Jpn. Pat. Appln. KOKAI Publication No. 2000-289215. The following technique is described in the Jpn. Pat. Appln. KOKAI Publication No. 2000-289215. A power off timer is disposed which starts a timing operation and turns off a breaker after an elapse of a predetermined time, when a power switch is turned off. When the breaker is turned off, an operation power supply into the image forming apparatus is cut off.
The image forming apparatus sometimes executes an initial filling operation of filling an ink liquid into an ink channel extending to an image forming head (ink head) from an ink cartridge. A user sometimes turns off the power switch, while the initial filling operation is being executed. Even in this case, by the timing operation of the power off timer, the breaker is turned off upon lapse of the predetermined time from the moment the power switch is turned off. Therefore, the supply of the operation power of the image forming apparatus is continued until the initial filling operation ends. Accordingly, the initial filling operation is securely achieved.
In the image forming apparatus of the ink jet system, the ink liquid is ejected from the ink head to form the image onto the image forming medium. The ink liquid remains in opening tips of nozzle holes in the ink head even in a standby state in which any ink liquid is not ejected from the ink head. When the power supply of the image forming apparatus is interrupted in this state, the next power supply is waited for in a state in which the ink liquid remains in the opening tips of the nozzle holes in the ink head.